Diamond



FIG. 1 is a top plan view of the claimed design;

FIG. 2 is a side elevational view with sub facets, the opposite side view being identical;

FIG. 3 is a side elevational view without sub facets, the opposite side view being identical; and,

FIG. 4 is a bottom plan view. 

CLAIM The ornamental design for a diamond, as shown and described. 